Make superglue's gemspec more conservative

[jho406]

I think making superglue’s gemspec a bit more conservative might make sense. Right now it uses.

  s.add_dependency "actionpack", ">= 7.0.0"
  s.add_development_dependency "activerecord", ">= 7.0"

Which says that it works with all future version of Rails. This isn’t 100% true as there’s a few monkey patches in `superglue_rails` that may not be compatible with future Rails versions.

We could be a bit more explicit and twiddle-wakka the versions.